A new design formula to estimate wave transmission on cubipod homogeneous low-crested structures

This study presents a new explicit empirical formula to estimate wave transmission on Cubipod Homogeneous Low-Crested Structures (HLCS) under depth-limited breaking wave conditions. The formula was derived using Artificial Neural Networks (ANN) to identify and quantify the influence of nineteen candidate explanatory variables on the squared wave transmission coefficient, K T 2 . A total of 210 two-dimensional physical model tests conducted at the Universitat Politècnica de València (Spain) were used to calibrate the formula. The dimensionless crest freeboard using the nominal diameter ( R c /D n50 ) and the dimensionless incident wave height at the structure toe using the water depth ( H m0,I /h s ) were identified as the most relevant explanatory variables. A new two-variable formulation with 3 fitting-parameters was found to estimate the proportion of transmitted energy, K T 2 , with a coefficient of determination R 2 = 0.89. The proposed formula was also applied to an external dataset of experimental tests on Cubipod HLCS previously reported in the literature. The results demonstrated a significantly better agreement than existing empirical formulas confirming the robustness and applicability of the new formula. The proposed formula is a reliable and easy-to-apply new tool for the preliminary design of emerged and submerged undamaged HLCS in depth-limited breaking wave conditions. The new explicit formula is particularly suited for low-crested structures aimed at combining coastal protection and ecosystem enhancement, such as artificial reefs in coral environments. • The dimensionless variables, R c /D n50 , and , H m0,I /h s , are the most relevant explanatory variables to estimate K T 2 of Cubipod Homogeneous Low-Crested Structures. • The proposed 3-parameter formula f( R c /D n50, H m0,I /h s ) provides better estimations than the formulas given in the literature. • The proposed 3-parameter formula is easy to use and is valid for HLCS with −1.35 ≤ R c / D n 50 ≤ 2.61, 0.07 ≤ H m 0 , I / h s ≤ 0.98, under depth-limited wave breaking conditions. • The simple and precise new explicit formula is particularly suited for Homogeneous low-crested structures aimed at combining coastal protection and ecosystem enhancement.